The present invention relates to an internal manifold type laminated fuel cell.
There has been devised and demonstrated a molten-carbonate type laminated fuel cell as shown in FIG. 1. An electrolytic plate in the form of a tile 1 is of the matrix type in which a carbonate such as Li.sub.2 CO.sub.3 --K.sub.2 CO.sub.3 eutectic impregnated into porous materials or of the paste type in which a carbonate and its support materials are molded by a press. The tile 1 is sandwiched between a cathode 2 and an anode 3 and a fuel 5 such as H.sub.2 gas is supplied to the anode 3 while an oxidizing gas 4 comprising air containing CO.sub.2 is supplied to the cathode 2. Then the followning reaction takes place on the side of the cathode 2: EQU 1/2 O.sub.2 +CO.sub.2 +2e.sup.- .fwdarw.CO.sub.3.sup.-
and the following reaction takes place on the side of the anode 3: EQU CO.sub.3.sup.2- +H.sub.2 .fwdarw.CO.sub.2 +H.sub.2 O+2e.sup.-
As a result, electric power is produced due to the potential difference between the cathode 2 and the anode 3 which sandwich the tile 1 which is a carbonate-ion conductor. The cathodes, tiles and anodes are laminated through current collectors 6 into a stack, whereby a voltage is increased. In order to make the lamination compact in size, the current collector 6 may be in the form of a separator plate 8 which is corrugated as indicated by 7 so that the oxidizing gas 4 and the fuel 5 are introduced to the cathode 2 and the anode 3, respectively.
However, the laminated fuel cell as shown in FIG. 1 is an internal manifold system (internal branching) so that the oxidizing gas 4 and the fuel 5 are separately introduced through the tile 1 and the separator plate 8 in each layer to the cathode 2 and the anode 3, respectively, and then are discharged. Therefore, highly reliable sealability must be maintained. That is, because H.sub.2 and O.sub.2 coexist at high reaction temperatures (which are controlled between 600.degree. and 700.degree. C.), there is a danger of explosion of the H.sub.2 and O.sub.2 mixture; as a result, highly reliable sealability is very important. Furthermore, the laminated fuel cells must be simple in construction so that they can be assembled in a simple manner. Moreover, in order to improve the efficiency, the oxidizing gas 4 and the fuel 5 must be uniformly distributed over the surfaces of the cathode 2 and the anode 3, respectively.
In view of the above, the present invention has for its object to provide a laminated fuel cell which is simple in construction and in which an oxidizing gas and a fuel are separately fed to and discharged from a cathode and an anode while ensuring highly reliable sealability and uniform distribution.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments thereof taken in conjunction with the accompanying drawings.